The Application Of Tea Polyphenol-Fe Coordination Polymer In Tumor Imaging And Treatment

Coordination polymer is a kind of coordination compound with neat network structure,which is formed by combining coordination bonds between metal ions and organic ligands.Coordination polymer nanoparticles can have the advantages of both nanomaterials and coordination polymers and showing a broad prospect of medical application.Tea polyphenols,as a natural,safe,readily available and diverse organic matter,are very suitable for the preparation of coordination polymer nanoparticles as organic ligands.Among them,Fe-polyphenol complexes not only have stable structure and good biocompatibility,but also have strong near-infrared absorption and excellent magnetic properties,which have a broad application prospect in the diagnosis and treatment of cancer.Therefore,in this paper,Tea polyphenol-Fe coordination polymer was used as the platform to carry out the following two works.In the first part,we studied the use of EA-Fe coordination polymer in magnetic resonance and photoacoustic dual-mode imaging of tumor.We first prepared and characterized a new nanoparticle EA-Fe@BSA nanoparticle.The nanoparticle has the advantages of easy preparation,small particle size,stability and good biological safety.The strong near-infrared region absorption makes it have excellent photothermal performance.MR imaging of the nanoparticles was performed on 0.5 T magnetic resonance imaging instrument,the study on solution level and in vivo level proved that EA-Fe@BSA nanoparticles had excellent T₁-weighted MR imaging effect.Meanwhile,in the photoacoustic imaging at the living body level,the strong near-infrared region absorption of EA-Fe@BSA nanoparticles not only showed excellent photothermal effect,but also showed good photoacoustic imaging effect.Therefore,the nanoparticle has a good application prospect in magnetic resonance imaging and photoacoustic dual-mode imaging in tumor.In the second part,we studied the use of TA-Fe coordination polymer for MRI-mediated photothermal therapy of tumor.We first prepared and characterized a new nanoparticle TA-Fe@BSA nanoparticle.The results of in vitro experiments showed that the TA-Fe@BSA nanoparticles had the advantages of small size,stability and excellent photothermal performance.Then,the solution level MRI experiment was conducted to test the magnetic resonance imaging effect of the nanoparticle under various magnetic fields,proving that the TA-Fe@BSA nanoparticle was superior to EA-Fe@BSA and GA-Fe@BSA nanoparticle,and even close to the T₁-weighted MR imaging effect of Gd-DTPA.Cell toxicity test and hemolysis test to determine its biological safety,experiments were carried out at the living body level.Experimental results showed that TA-Fe@BSA coordination polymer nanoparticles have the potential to be used as MRI contrast agents and photothermal treatment agents,and have a good application prospect in the efficient diagnosis and treatment of tumor.